This Application is a U.S. National Phase Application of PCT International Application PCT/JP99/05869.
The present invention relates to the field of detectors used for monitoring the output power of radio devices, typically mobile communications equipment.
Rapid expansion is taking place in the mobile communications field, and the sudden increase in number of users has led to the mixed use of multiple systems. Accordingly, a composite terminal that accepts multiple systems is desirable for radio devices for monitoring the output power of individual systems separately.
On the other hand, further downsizing is desirable for radio circuits in the mobile communications field, increasing the need for unifying individual detectors used in multiple systems to reduce the detector size.
The detector of the present invention includes a first transmission line, a second transmission line disposed near the first transmission line, and a third transmission line disposed near the first transmission line. A terminating resistor is connected to one end of the first transmission line, and the other end of the first transmission line is connected to an anode terminal of a detecting diode through a wideband matching circuit. A cathode terminal of the detecting diode is connected to a load circuit.
The above configuration enables to detect two predetermined frequency bands separately with predetermined coupling for realizing a small wideband detector.